Powershell Where-Object and DN exclusions - powershell

Question

I am trying to query a list of users while excluding a specific OU. This is also using Quest's AD snap-in for Get-QADUser. I have this:
$ExcludedOU = "Service Accounts"
$inactiveUsers = Get-QADUser -SizeLimit 3 -SearchRoot $sourceOu -NotLoggedOnFor $InactiveFor -Enabled | Where-Object {$_.description -notlike $DescriptionPrefix -and #{n="ParentContainerDN";e={($_.ParentContainerDN -split ",*..=")[0]}} -notlike $ExcludedOU }
The goal is to exclude any users where the parent OU is "Service Accounts". ParentContainerDN looks like OU=Service Accounts,OU=Our Users,DC=DOMAINNAME,DC=ORG
This query does not error, but it does not exclude either. This is the part I may not have the syntax correct on?
#{n="ParentContainerDN";e={($_.ParentContainerDN -split ",*..=")[0]}} -notlike $ExcludedOU

Answer 1

I was partially wrong about the regex portion of your split. I am still correct in that the string supports regular expressions. That query will split on the CN=, OU= and DN=.
However you placed calculated property syntax into a where-object clause. It didn't error out since it is a valid hashtable and hashtables support like and notlike. Calculated properties are used for things like Format-Table and Select-Object which you can then reference those "new" properties later in other pipes.
$inactiveUsers = Get-QADUser -SizeLimit 3 -SearchRoot $sourceOu -NotLoggedOnFor $InactiveFor -Enabled |
Select-Obejct Name,SamAccountName,Description,#{n="ParentContainerDN";e={($_.ParentContainerDN -split ",*..=")[0]}} |
Where-Object {$_.description -notlike $DescriptionPrefix -and $_.ParentContainerDN -notlike $ExcludedOU }
The above syntax is what was also done in the code you linked to on Social Technet
I cannot make this return false for the life of me. This will evaluate to true which might be why your query was not working as expected. This is valid PowerShell just not correct to use.
#{n="ParentContainerDN";e={$_.WhatEver}} -notlike "string"
However like Kai Zhao mentioned in comments this is not really used effectively and you can get the same results without the calculated property.
$inactiveUsers = Get-QADUser -SizeLimit 3 -SearchRoot $sourceOu -NotLoggedOnFor $InactiveFor -Enabled |
Where-Object {$_.description -notlike $DescriptionPrefix -and ($_.ParentContainerDN -split ",*..=")[1] -notlike $ExcludedOU}